Pages

May 28, 2011

It help ip network devices find other device on the same segment or Vlan |ـــــ ARP uses a local broad cast to discover neighboring device |ـــــ ARP resolves ip addresses to mac addresses so that machines on the same data link layer media can communicate with each other.

It is used to send error & control information between ip network devices.

There are many diffident messages that can be shared, including the following:

1. Echo request: Determines whether on ip node ( a host or a router is available on network.)
2. Echo Reply: Replies to ICMP echo request.
3. Destination Unreachable: Informs the host that a datagram can't be delivered.
4. Source Quench: Informs the host to lower the rate at which it sends datagram because of congestion.

May 21, 2011

A datagram is a basic transfer unit associated with a packet-switched network in which the delivery arrival time and order are not guaranteed. A datagram consists of header and data areas, where the header contains information sufficient for routing from the originating equipment to the destination without relying on prior exchanges between the equipment and the network. The source and destination addresses as well as a type field are found in the header of a datagram.

May 4, 2011

Before i start this article i should say don't worry if you can't understanding it! you can see the fast way!

- In class C address, only 8 bits are available for defining the hosts.
- Remember that subnet bits start at the left & go to the right without skipping bits.
- This means that the only class C subnet mask can be following.

This command allows you to use first & last subnet in your network design.
FOR EXAM:
The class C mask of 192 provides subnets 64 & 128.
BUT with the ip subnet-zero command, you now get to use subnets 0 , 64, 128 & 192.
* that is two more subnets for every subnet mask use.